Spousal benefits

I will qualify to claim benefits under my ex husband's name (divorced and deceased). I plan to continue working probaby until 70. I also plan on moving to Canada (I am a Canadian citizen with U.S. residency).

Question1: should I claim his benefits at 62 (with penalty and deduction) or wait until full retirement at 67? and then at 70 switch to mine...

Question 2: Can I work remotely from Canada (for current U.S. employer) and continue contributing to the U.S. tax system and social security instead of the Canadian one?